The Product Backlog is an ordered list of everything that is known to be needed in the product. It is the single source of truth for the Scrum Team and the stakeholders. It contains all the requirements, features, functions, enhancements, fixes, and anything else that can deliver value to the customers and users of the product.

The Product Owner is accountable for ordering the Product Backlog. The Product Owner orders the items in the Product Backlog based on factors such as value, risk, priority, dependency, feedback, or market conditions. The order of the Product Backlog items provides a clear and consistent indication of what is most important and urgent for the product. The order of the Product Backlog items also helps the Scrum Team and the stakeholders to plan and forecast effectively.

The tools and techniques used to create, manage, or refine the Product Backlog are not a valid consideration when ordering the Product Backlog. The tools and techniques are means to an end, not an end in themselves. The tools and techniques do not affect the value or quality of the product or service delivered. The tools and techniques may vary from one Product Owner to another, depending on their preferences, skills, or context. The tools and techniques may also change over time, as new technologies or practices emerge or evolve.